1. Field of the Invention
This patent relates to packaging for products such as washers, dryers and refrigerators. More particularly, this patent relates to an extruded plastic corner post for protecting packaged products from axial and lateral forces.
2. Description of the Related Art
Warehousing and distribution environments drive the need for devices that protect products from both axial (vertical) and lateral (horizontal) forces. Axial forces mainly are caused by stacking packaged products in warehouses. Lateral forces can be caused by stacking, clamp handling and basiloid handling, and also by collisions inherent in warehouse and distribution systems. For instance, it is not uncommon to move packaged appliances using clamp trucks in a block three units high, three units across and two units deep. Such clamp handling can impart lateral forces on the packaged products of up to 2,500 PSI.
Laminated corner posts consisting essentially of hollow paper tubes are a popular means for supporting and cushioning the corners of packaged appliances during storage and transport. When subjected to large lateral forces, many laminated paper corner posts comprises beaded structures that are designed to fold over on themselves. Once the paper corner post is folded upon itself, the lateral force is directed through the folded corner post to the structural frame of the packaged appliance, thereby protecting the relatively weaker sidewalls. Although paper corner posts that fold over and lose their original shape are well suited to protect appliances from damage, they do not prevent the container surrounding the appliance from collapsing inwardly when the container is subjected to large lateral forces. Laminated paper support posts also can degrade in high humidity or wet conditions, which can occur during assembly line product testing.
Thus it is a primary object of the present invention to provide an improved corner post that can withstand vertical and lateral forces without the foldover effect found with laminated paper posts.
Another object of the invention is to provide a corner post that does not degrade in high humidity or wet conditions.
Still another object of the invention is to provide a corner post that maintains the distance between the container and the product, thereby preventing the container from collapsing inwardly.
Yet another object of the present invention is to provide a corner post having enhanced axial strength.
Further and additional objects will appear from the description, accompanying drawings, and appended claims.
The present invention is an elongated extruded plastic corner post for protecting a packaged product. In one embodiment referred to as the tube type corner post, the corner post comprises an outer wall and an inner wall joined at the ends to define a substantially L-shaped cylindrical space therebetween, and one or more integrally formed ribs connecting opposing faces of the inner and outer walls. The ribs may be planar or arcuately shaped. If the ribs are planar, they may be perpendicular to the inner and outer walls or set obliquely thereto.
The tube type corner post may be formed with cut out portions to accommodate and protect protruding components of the packaged product, such as handles and the like. The inner and outer walls of the corner post may be formed with beads to enhance the axial strength of the post.
The tube type corner post is best used with appliances and other products having thin walls mounted on a relatively strong structural framework. The tube type corner post protects the packaged product by directing lateral forces directly to the structural framework.
In another embodiment, the extruded corner post comprises two elongated legs joined along an inner corner and forming a spring-like profile. Each leg of the spring-like profile corner post comprises a planar inner segment extending from an inner corner and terminating at a first bend, a rib extending from the first bend outwardly to a second bend, and a planar outer segment extending from the second bend along a plane substantially parallel to the plane of the inner segment. The inner segment, rib and outer segment are integrally formed by a plastic extrusion process.
The spring-like profile corner post absorbs lateral shocks to the container by flattening or compressing. When the lateral force subsides, the corner post returns to its original shape.